package sampleInLucene;

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.io.File;
import java.io.IOException;
import java.util.Date;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.index.FilterIndexReader;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.queryParser.QueryParser;
import org.apache.lucene.search.Collector;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.Scorer;
import org.apache.lucene.search.TopDocsCollector;
import org.apache.lucene.search.TopScoreDocCollector;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.util.Version;

/** Simple command-line based search demo. */
public class SearchFiles {
	private static class OneNormsReader extends FilterIndexReader {
		private String field;

		public OneNormsReader(IndexReader in, String field) {
			super(in);
			this.field = field;
		}

		public byte[] norms() throws IOException {
			return in.norms(this.field);
		}
	}

	private SearchFiles() {
	}

	public static void main(String[] args) throws Exception {
		String usage = "Usage:\tjava org.apache.lucene.demo.SearchFiles [-index dir] [-field f] [-repeat n] [-queries file] [-raw] [-norms field] [-paging hitsPerPage]";
		usage += "\n\tSpecify 'false' for hitsPerPage to use streaming instead of paging search.";
		if (args.length > 0
				&& ("-h".equals(args[0]) || "-help".equals(args[0]))) {
			System.out.println(usage);
			System.exit(0);
		}

		String index = "index\\indexed";
		String field = "contents";
		String queries = null;
		int repeat = 0;
		boolean raw = false;
		String normsField = null;
		boolean paging = true;
		int hitsPerPage = 10;

		for (int i = 0; i < args.length; i++) {
			if ("-index".equals(args[i])) {
				index = args[i + 1];
				i++;
			} else if ("-field".equals(args[i])) {
				field = args[i + 1];
				i++;
			} else if ("-queries".equals(args[i])) {
				queries = args[i + 1];
				i++;
			} else if ("-repeat".equals(args[i])) {
				repeat = Integer.parseInt(args[i + 1]);
				i++;
			} else if ("-raw".equals(args[i])) {
				raw = true;
			} else if ("-norms".equals(args[i])) {
				normsField = args[i + 1];
				i++;
			} else if ("-paging".equals(args[i])) {
				if (args[i + 1].equals("false")) {
					paging = false;
				} else {
					hitsPerPage = Integer.parseInt(args[i + 1]);
					if (hitsPerPage == 0) {
						paging = false;
					}
				}
				i++;
			}
		}

		IndexReader reader = IndexReader
				.open(FSDirectory.open(new File(index)));

		if (normsField != null)
			reader = new OneNormsReader(reader, normsField);
		IndexSearcher searcher = new IndexSearcher(reader);
		Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_34);
		QueryParser parser = new QueryParser(Version.LUCENE_34, field, analyzer);

		if (queries == null) // prompt the user
			System.out.println("Enter query: ");
		String line = "path";
		Query query = parser.parse(line);
		System.out.println("Searching for: " + query.toString(field));

		if (repeat > 0) { // repeat & time as benchmark
			Date start = new Date();
			for (int i = 0; i < repeat; i++) {
				searcher.search(query, null, 100);
			}
			Date end = new Date();
			System.out.println("Time: " + (end.getTime() - start.getTime())
					+ "ms");
		}

		if (paging) {
			doPagingSearch(line, searcher, query, hitsPerPage, raw,queries == null);
		} else {
			doStreamingSearch(searcher, query);
		}

		reader.close();
	}

	/**
	 * This method uses a custom HitCollector implementation which simply prints
	 * out the docId and score of every matching document.
	 * 
	 * This simulates the streaming search use case, where all hits are supposed
	 * to be processed, regardless of their relevance.
	 */
	public static void doStreamingSearch(final IndexSearcher searcher,
			Query query) throws IOException {
		Collector streamingHitCollector = new Collector() {
			private int docBase;
			Scorer scorer;

			// simply print docId and score of every matching document
			public boolean acceptsDocsOutOfOrder() {
				return false;
			}

			public void collect(int doc) throws IOException {
				System.out.println("doc=" + doc + " score=" + scorer);
			}

			@Override
			public void setNextReader(IndexReader reader, int docBase)
					throws IOException {

			}

			public void setScorer(Scorer arg0) throws IOException {
				scorer = arg0;
			}
		};
		searcher.search(query, streamingHitCollector);
	}

	/**
	 * This demonstrates a typical paging search scenario, where the search
	 * engine presents pages of size n to the user. The user can then go to the
	 * next page if interested in the next hits.
	 * 
	 * When the query is executed for the first time, then only enough results
	 * are collected to fill 5 result pages. If the user wants to page beyond
	 * this limit, then the query is executed another time and all hits are
	 * collected.
	 * 
	 */
	// public static void doPagingSearch(BufferedReader in, Searcher searcher,
	// Query query,
	// int hitsPerPage, boolean raw, boolean interactive) throws IOException {
	public static void doPagingSearch(String line, IndexSearcher searcher,
			Query query, int hitsPerPage, boolean raw, boolean interactive)
			throws IOException {

		// Collect enough docs to show 5 pages
		TopDocsCollector collector = TopScoreDocCollector.create(hitsPerPage,
				true);
		searcher.search(query, collector);
		ScoreDoc[] hits = collector.topDocs().scoreDocs;

		int numTotalHits = collector.getTotalHits();
		System.out.println(numTotalHits + " total matching documents");

		int start = 0;
		int end = Math.min(numTotalHits, hitsPerPage);

		while (true) {
			if (end > hits.length) {
				System.out
						.println("Only results 1 - " + hits.length + " of "
								+ numTotalHits
								+ " total matching documents collected.");
				System.out.println("Collect more (y/n) ?");
				// String line = in.readLine();
				if (line.length() == 0 || line.charAt(0) == 'n') {
					break;
				}

				// collector = new TopDocsCollector(numTotalHits);
				searcher.search(query, collector);
				hits = collector.topDocs().scoreDocs;
			}

			end = Math.min(hits.length, start + hitsPerPage);

			for (int i = start; i < end; i++) {
				if (raw) { // output raw format
					System.out.println("doc=" + hits[i].doc + " score="
							+ hits[i].score);
					continue;
				}

				Document doc = searcher.doc(hits[i].doc);
				String path = doc.get("path");
				if (path != null) {
					System.out.println((i + 1) + ". " + path);
					String title = doc.get("title");
					if (title != null) {
						System.out.println("   Title: " + doc.get("title"));
					}
				} else {
					System.out.println((i + 1) + ". "
							+ "No path for this document");
				}

			}

			if (!interactive) {
				break;
			}

			if (numTotalHits >= end) {
				boolean quit = false;
				while (true) {
					System.out.print("Press ");
					if (start - hitsPerPage >= 0) {
						System.out.print("(p)revious page, ");
					}
					if (start + hitsPerPage < numTotalHits) {
						System.out.print("(n)ext page, ");
					}
					System.out
							.println("(q)uit or enter number to jump to a page.");

					// String line = in.readLine();
					if (line.length() == 0 || line.charAt(0) == 'q') {
						quit = true;
						break;
					}
					if (line.charAt(0) == 'p') {
						start = Math.max(0, start - hitsPerPage);
						break;
					} else if (line.charAt(0) == 'n') {
						if (start + hitsPerPage < numTotalHits) {
							start += hitsPerPage;
						}
						break;
					} else {
						int page = Integer.parseInt(line);
						if ((page - 1) * hitsPerPage < numTotalHits) {
							start = (page - 1) * hitsPerPage;
							break;
						} else {
							System.out.println("No such page");
						}
					}
				}
				if (quit)
					break;
				end = Math.min(numTotalHits, start + hitsPerPage);
			}

		}

	}
}
